m2Cygni
| catalogues and names | m2Cyg, NSV 25756, 78 Cyg, HR 8310, HD 206827, SAO 89939, WDS 21441+2845B |
| constellation | Cygnus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 21h 44min 8,3sec | DEC: +28° 44' 35'' |
| position (J1900) | RA: 21h 39min 40,3sec | DEC: +28° 17' 26'' |
| proper motion (J2000) | RA: 0,231 arcsec/a | DEC: -0,219 arcsec/a |
| radial velocity | 17 km/s note: suspected variable radial velocity |
|
| trigonometric parallax | 0,049 arcsec | |
| note (category: dynamical parallaxes): | 0.052". |
magnitude
| visual magnitude | 6,08 (original HR magnitude) |
spectral / color information
| spectral class | G2V |
| B-V-magnitude | 0,36 (uncertain) |
double/multiple star system information
| number of components of multiple star system | 5 |
| separation | 2 arcsec |
| mag difference (of double or brightest multiple) | 1,3 |
| component ID | AB |
| note (category: double and multiple data): | See HR 8309. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 21h 44min 8,312sec | DEC: +28° 44' 35,27'' | ±1,24 arcsec | source: 29 |
| proper motion (J2000) | RA: 0,0176 arcsec/a | DEC: -0,219 arcsec/a | source: 25 | |
| radial velocity | 17 km/s | source: 25 | ||
| trigonometric parallax | 0,049 | ±0,005 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 80,59° | latitude: -18,34° | ||
| GCI unit vector (J2000) | X: 0,727183 | Y: -0,489852 | Z: 0,480884 | |
magnitude:
| visual | 6,11 (observed) | source: 25 |
| photovisual | 6,1 | source: 2 |
| photographic | 6,5 | source: 2 |
spectral information:
| spectral class | F5 | source: 29 | |
| Morgan-Keenan | G2V | source: 25 | |
| B-magnitude | 6,68 ±0,05 | B-V-magnitude | 0,57 |
double/multiple star system information:
| separation between brightest and second brightest component | 2,1 arcsec |
| magnitude difference between brightest and second brightest component | 1,4 |
| position angle | 305 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 4,77 | F5 | m1Cygni, 78 Cyg, HR 8309, HD 206826, SAO 89940 |
| B | 6,11 | F5 | m2Cygni, 78 Cyg, HR 8310, HD 206827, SAO 89939 |
sources:
| 2 | HD and HDE Catalogs |
| Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
| 29 | SAOJ2000 |
| SAO on FK5 at J2000, 1989 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (J1950) | RA: 21h 41min 54,183sec | DEC: +28° 30' 57,84'' | ±0,04 arcsec |
| position (J2000) | RA: 21h 44min 8,312sec | DEC: +28° 44' 35,27'' | |
| proper motion J1950 (FK4) | RA: 0,0174 arcsec/a | DEC: -0,215 arcsec/a | ±0,005 arcsec/a in RA ±0,006 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0176 arcsec/a | DEC: -0,219 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 6,1 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | F5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
remarks for duplicity and variability
| Double star in Aitken's Double Star Catalogue (Aitken 1932) |
catalogues
| source catalogue | GC, catalogue number: 30437 |
| Durchmusterung | BD+28 4169B |
| Boss General Catalogue | 30437 |
| Henry Draper Catalogue | 206827 |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 21h 44,1min | DEC: +28° 45' |
| proper motion (J2000) | RA: 0,288 arcsec/a | DEC: -0,241 arcsec/a |
double/multiple star system information:
| component | year | number of measures | position angle | angular separation | magnitude of 1st component | magnitude of 2nd component | spectral class(es) | discoverer code |
| AB | 1823 | often | 109° | 5,6'' | 4,7 | 6,1 | F6V G2V | STF2822 |
| 1994 | 305° | 2,1'' | ||||||
| AC | 1878 | 11 | 263° | 35,3'' | 4,7 | 11,5 | - | STF2822 |
| 1987 | 289° | 68,2'' | ||||||
| AD | 1823 | 24 | 61° | 217,4'' | 4,7 | 6,9 | F7V F2V | STF2822 |
| 1956 | 52° | 199'' | ||||||
| BD | 1902 | 2 | 54° | 206,1'' | 6,1 | 6,9 | A5 | STF2822 |
| 1909 | 53° | 204,7'' |
discoverer information:
| discoverer code | discoverer | reference |
| STF2822 | Struve, F.G.W. | - |
notes:
| note | Mu Cyg. P = 789yr., a = 5.32", motion direct. The A component is a double-lined spectroscopic binary. AB: H III 15. D is the principal component of ES 521. |
data from 4th Catalog of Orbits of Visual Binaries (Worley+, 1983)
position:
| position (J1900) | RA: 21h 39,7min | DEC: +28° 17' |
magnitudes, spectral classes, orbital elements:
| author: | W.D. Heintz |
| date of observation: | 1965 |
| magnitude of component A: | 4,78 |
| magnitude of component B: | 4,78 |
| spectral class component B: | F7V |
| spectral class component B: | F7V |
| period [y]: | 507,5 |
| semi-major axis [arcsec]: | 4,278 |
| inclination [deg]: | 76,5 |
| node [deg]: | 109,6 |
| equinox of node: | 2000 |
| eccentricity: | 0,58 |
| time of periastron passage: | 1962,5 |
| dates of ephemeris: | 1965-1990 |
| grade: | preliminary |
| reference: | Veroff. Sternw. Munchen 7, 26; 1966. |
| other name(s) | STF 2822, Mu Cyg |